Artificial arm



A. A. GEORGE Sept. 18, 1934.

ARTIFICIAL ARM 2 SheetS -Sheet 1 Filed Aug. 23, 1933 Sept. 18, 1934.

A. A. GEORGE ARTIFICIAL ARM Filed Aug. 23, 1933 2 Sheets-Shea; 2

Inventor 4419220214 fozye By v flllorney ance with the present invention is for use where,

Patented Sept. 18, 1934 UNITED STATES PATENT OFFICE 1373,1305 1 Application August 2a, 1933, Serial No. 686,456

4 Claims. (c1. 3-42) This invention relates to the class of artificial limbs and has more particular reference to artificial arms. 7

More particularly the artificial arm in accordan amputation is below the elbow. I p

An important object of the present invention is in the provision of an artificial arm which may be worn without the use of a harness as is now generally required; is efficiently balanced-and has an improved locking device for attaching to the arm, in a quick detachable manner, an artificial hand, hook or other attachment. 7

The invention together with its objects and, advantages will be best understood from a study of the following description, taken in connection with the accompanying drawings wherein:

Figure 1 is a front elevational viewof the arm,

Figure 2 is a side elevational view thereof.

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure 1.

Figure 4 is an end elevational view of the forearm socket.

Figure 5 is an enlarged sectional view through the free end of the fore arm socket for illustrat ing the locking device.

Figures 6 and 7 are sectional views taken substantially on the lines 6-6 and 7-7 respectively of Figure 5.

Figure 8 is a fragmentary elevational view of one end of the latch bar and Figure 9 is a plan view of a key.

Referring to the drawings by reference numerals it will be seen that the socket for the fore arm stump is designated generally by the reference numeral 10 and comprises a substantially elongated frusto-conical body 11 of suitable material, preferably leather, mounted in a frame having narrow elongated sides 12 extending longitudinally of the body 11 and integral at the lower end of the socket with the continuous rim 13 of a bottom plate 14. As shown, plate 14, rim 13 and side frame pieces 12 are integral and are of metal. The smaller end of the body 11 fits snugly within the confines of the rim 13 and the frame members 12 are riveted to opposite sides of the member 11 asshown at one side of the longitudinal median of the body 11. In thepresent instance the frame bars 12 are located forwardly of the longitudinal median or the body 11 as will be clearfrom a study of Figure 2. An arcuate metal plate 15 extends across the front side of the body 11 at the upper or elbow end of the body 11. The plate 15 is formed of metal, is of any suitable width and has its end edges secured to the frame members 12, preferably as by being integral with said frame members. At the side thereof opposite to the metal piece 15 or in other words at the rear side of the member 11 adjacent the upper or elbow end thereof, said mem- 0 ber 11 is splitlongitudinally and the edges formed by the slitare drawn together by suitable lacingS 16, For the split there is provided on the inside ofithe member 11 a suitable tongue 1'7.

Adapted to embrace the stump arm above the V elbow is alongitudinally split sleeve 18 of leather and the same is adapted to be loosely secured about said, stump arm above the elbow through the medium of a suitable strap 19. Frame members 20 areriveted to thesleeve 18 at opposite sides thereof b and at the rear side of the longitudinalmedian of the sleeve 18. as will be clear from a study of Figure 2.

.At the elbow end thereof the frame members 20extend beyond the end of the sleeve 18 and are outwardlyoffset and are hinged to the elbow ends of the frame members 12 as at 21.

The frame members 20 adjacent the upper and lower ends of the sleeve 18 are connected by relatively narrow curved metallic pieces 22 so that extend across the back of the sleeve 18, or in other wordsextend across the side of the sleeve is opposite to the plate 15.

The edges of the sleeve 18 at the upper and lower'ends thereof are cut on a bias as shown 5 and at said upper and lower ends the rear portions of the sleeve -18 are flared as at 23, 24. For relievingithe fore arm stump of practically all weight there is provided a balance spring 24 which is anchored to a tab 25 secured on the front sideiof the socket body 11 to the left of the longitudinal center of the socket. The upper end of the spring 24 is connected by an adjustable strap 26 :to the sleeve 18in substantial alinement with the tab 25. V

In the lower end of the arm 10 there is provided'a lock device for a quick detachable connection to said arm of a work hook or other suitable attachment indicated generally .by the refer-l ence numeral 27. The said lock device comprises an L-shaped latch member one limb 28 of which is disposed parallel to the plate 14 as shown in Figure 3 and is provided at its free end'with a downturned flange to which is fixed a pin 29 that operates in a suitable aperture therefor pro- 5 vided' in the rim 14. Disposed about the pin 29 is Laooil spring 30 that yieldably urges the latch member 28 toward the right in Figure 5. The vertical limb 31 of theflatchmember is provided with an opening to accommodate a shouldered 11 portion of the head 32 of a screw threaded pin 33. Clamped on the head 32 of said pin between the limb 31 and a nut 34 threadedly engaged with said pin is a cam 35 to turn with the pin 33.

An L-shaped spring member has one limb 36 thereof riveted or otherwise secured between the socket body 11 and the frame member 12 at that side of the arm opposite to the limb 31 of the latch member. Said spring member has its second limb 37 extending transversely of the socket body 11 with its free end normally in the path of the limb 31 of the latch member to prevent movement of the latch member toward the left in Figure 5, that is, to a releasing position.

The cam 35 is provided for moving the me end of the spring limb 37 out of the path of the limb 31 of the latch and for rotating thepin33 to move the cam 35 into and out of engagement with the spring limb 3"! there may be employed either an operating stem 39 that has one end adapted to be'screw threadedly engaged with the head 32 as shown in Figure 5, or a key such as shown in Figure 9 and indicated by the reference numeral 40. The key 40 has a'squared' end adapted to be fitted in a squared socket 41 provided therefor in the head 32. Obviously touse'the key 40 the stem 39 is unscrewed and the squared end of the key 40 is inserted in-the socket 41 of the head 32 and when'so engaged with the socketthe key 40 may be then rotated torotate the-cam 35 for moving the cam into the full line position shown in Figure 6 to raise the spring member 37 out of the path of the latch stem 31,0rto the dotted line positon shown in Figure 6' to permitthe free end of the spring member 37 to spring downwardly intothe path of'the latch stem 31 for preventing movement of the latch to a release position.

The lock above described is'especially' designed to accommodate those types of attachments which as shown in the drawings include a head plate 40 having extending from one side thereof a pin 41 provided intermediate its ends with a circumferential groove-as shown in Figure 5. To accommodate the pin 41 the plate 14 is provided at its center with'an opening while the limb 28 of the latch is also provided with a suitable opening to accommodate the pin 41 and to engage the groove in the pin in a manner shown in Figure 5 to lock the attachment to the'artificial arm.-

It will be also noted from a study of Figures 5 and '7 that the limb 28' of the latch operates within a suitable guide 43 that is secured 'at its ends to the plate 14 and is'provided atits' raised intermediate portion with'asuita'ble opening to accommodate the pin 41; h I To eject the pin 41' upon release-of the same there is also provided a leaf spring 44 which is suitably anchored at one end, and which has its free end arranged to bear'against the inner end of the pin 41 in a manner clearly shown in Figures 3 and '5.

Obviously with the pin 41 engaged by the limb 28 of the latch as shown in Figure 5, and the cam 35 turned to the dotted line position shown in Figure 6, spring limb 37 will be arrangedin the path of the latch limb 31, the parts being such as to securely lock the attachment 27 to the end of the artificial arm. To release the attachment the stem 39, or the key 40 asthe case may be is rotated for placing the parts in the position shown in Figure 5, when pressure is then applied to the stem 39 or the key 40, as the case may be for moving the latch inwardly against the action. of

spring 30and so position the openin in the latch limb 28 as to release the pin 41. When the pin .from the following: When worn, the sleeve 18 is placed about the stump arm above the elbow and is loosely secured thereabout. The fore-arm stump is received in the upper or largest end of the socket 10, and without resistance from the wearer the balance spring 24 will normally main tain the artificial arm bent at the elbow at an angle of about twenty degrees so that the socket 10 will rest firmly on the front of the fore arm stump at the point where the plate 15 is located while the sleeve 18 will rest against the back of the upper stump-arm at the points where the straps 22 extend across the back of the sleeve.

Assuming that the attachment 27 is applied to the'artificial arm, it will be seen that when an object is being lifted the artificial arm will tend to straighten, alining the frame members 12 with the frame members 20, the connection between these frame members being such as, to limit the swinging of the socket 10 from the position shown in Figure 3 to the position shown in Figure 2. This straightening of the artificial arm against the action of spring 24 will cause what maybe termed a lever action of the arm over the front of the lower stump arm and under reinforcement plate 15 of the socket 10. As a result the sleeve 18 is drawn more firmly against the back of the upper stump arm at the reinforcing bands 22 affording maximum gripping power at this point. The flare 24 at the elbow end of the sleeve 18 under such conditions fitting just above the stump elbow will assist in preventing the artificial arm from slipping off of the stump arm and hence, with this improved artificial arm considerable weight may be lifted or carried whether or not the sleeve 18 is strapped about the stump arm above the elbow, and without resort to a harness or other devices as is now commonly required. Should however the wearer be lifting extremely heavy loads the grip on the back of the stump arm may be increased by the wearer slightly bending the stump arm at the elbow so that the end of the stump will more firmly bear against the inside of the socket 10 at the region of the reinforcing plate 15. An important feature of the present invention is the adjustable balance spring 24' which relieves the low-er stump arm of practically all weight of the socket 10 including the attachment 27, the weight being transmitted back of the upper stump arm through the sleeve 18 and the metallic pieces 22. The weight being so transmitted to the upper stump arm the sleeve 18 will hold firmly against the back of the stump arm with, as before mentioned, the flare 24 fitting just above the elbow of the stump arm, assisting in preventing slipping. By all the weight being thus carried on the upper stump arm the wearing of the artificial arm will not be unpleasant since the lower stump arm, that is, the part, of the stump below the elbow, will be relieved of substantially all weight.

In actual practice it has been found best results are obtained when the spring 24 is adjusted to ion iro-

degrees. As is apparent the spring 24 may be adjusted as found desirable and as may be required because of the weight of the attachment 27.

A still further feature of the invention is in having the lacing 16 located on the socket 10 at the back of the socket adjacent the elbow end thereof. This location of the lacing has been found in practice to be preferable to having the lacing on top of the socket for the reason that with the lacing in the last named position, whenever the arm is lifted to a horizontal position, the weight pulls the lacing down on the stump and continuous use causes the socket to bulge and irritate the end of the stump arm. By having the lacing arranged at the back of the artificial arm there is little or no pressure of the lacing against the stump.

A further feature of the invention is the provision of the reinforcing plate 15 which will be found especially desirable when the stump is short since under such conditions the plate will prevent the fore arm socket 10 from bulging at the end of the stump when the fore arm is raised at an angle under weight. In actual practice it has been found that were it not for this plate where the stump arm is short, for example say from one and one-half inches to four inches, the leather would bulge at the end of the stump; continuous wear will set this bulge in the leather which tends to irritate the stump arm.

Further by the provision of the plate 15 the socket 10 may, regardless of the length of the stump arm below the elbow, be formed of leather whereas heretofore when the stump of the arm below the elbow is exceedingly short a socket instead of being made of leather must be made of wood, composition or other suitable strong and durable material, making the construction more expensive than where leather is employed.

Having thus described my invention, what I claim as new is:

1. An artificial arm comprising a sleeve for engaging the upper arm of a stump, a socket for receiving the fore arm portion of the stump, rigid frame members secured to the socket at opposite sides thereof forwardly of the longitudinal median of the socket, other rigid frame members secured to opposite sides of the sleeve rearwardly of the longitudinal median of the sleeve, hinge means connecting the first named frame members with the second named frame members at the elbow of the artificial arm, and a balance spring at the front of the artificial arm connecting the sleeve and socket at one side of the longitudinal median of said sleeve and socket.

2. An artificial arm comprising a sleeve split longitudinally and adapted to engage the upper arm of a stump, straps engaged with the sleeve at opposite sides of the split for securing the sleeve loosely upon said upper arm of the stump, a tapered socket for reception of the stump of the fore arm, metallic straps secured to diametrically opposite sides of the socket forwardly of the longitudinal median thereof, other metallic straps secured to diametrically opposite sides of the sleeve rearwardly of the longitudinal median of said sleeve, means pivotally connecting the metallic straps adjacent the open end of the socket, a metallic wear plate extending between the first named straps across the front of the socket adjacent the open end of the latter, relatively narrow arcuate metallic plates extending between said other straps across the back of said sleeve, and said sleeve at the lower or elbow end thereof having its back portion flared as and for the purpose specified.

3. In an artificial arm, a hollow tubular member for reception of the stump of the fore arm and an attachment locking device arranged in the lower end of said member and including a slidably mounted latch member, a spring having an arm extending in the path of a part of said latch member, a cam rotatably mounted on said part of the latch member and engageable with the end of the spring to move the same out of the path of said part of the latch member, and manual means engageable with the cam for rotating the latter to control the operation of the lock.

4. In an artificial arm, a fore arm stump receiving socket, and an attachment locking device at the lower end of the socket and including a latch plate shiftable transversely across the bottom of the socket and provided with an opening for receiving the headed stud of the attachment, a spring device engaged with the latch plate and normally urging the same in one direction for locking engagement with the headed stud of the attachment, said latch plate having an angularly 115 disposed part, an angular spring member anchored within the socket and having a free limb arranged in the path of the angular part of the latch plate for normally engaging with said part of the latch plate to hold the same against move- 120 ment in a direction opposing the action of the first named spring device, a cam ro-tatably mounted on the angularly disposed part of the latch plate and engageable with the free limb of the spring for moving the same out of the path of 125 the latch plate and a rotatable supporting pin for the cam mounted on the angular part of the latch plate and provided at one end with a socket and provided internally for accommodating an operating member to be used in rotating the cam 1 for releasing the latch plate.

ARMOR A. GEORGE. 

